Food Chain and Food Webs

Food Chain, Food Webs and Decomposers

Food Chains: A food chain is a linear sequence of links in a food web starting from "producer" species (such as grass or trees) and ending at apex predator "decomposer" species (like grizzly bears or killer whales). A food shows how energy is transferred in the form of food from one organism to another.

Producers: A food chain starts with a producer. A producer is an organism which makes it's own food. Plants are an example of producers. They make their own food by the process called photosynthesis. Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar. This energy is later used to carry out life functions.

Consumers: Some organisms can not make their own food. They depend on other living organisms for food. These are called consumers. They may consume by various means such as may consume by various means, including predation, parasitization, and biodegradation. Consumers are categorized into three groups: primary consumers, secondary consumers, and the tertiary consumers.

  • Primary Consumers: Primary Consumers are consumers that feed directly on the producers. They are mainly Herbivores ( Animals that eat plants ). For example. caterpillar is a primary consumer that feeds on leaves.
  • Secondary Consumers: Secondary Consumers are animals that feed on the Primary Consumers. They are mainly Carnivores ( Animals that eat meat ) and Omnivores ( Animals that eat plants and meat )
  • Tertiary Consumers: Tertiary Consumers are animals that feed on the Secondary Consumers. They too are either Carnivores or Omnivores.

Food Webs: A food web  is the natural interconnection of food chains and generally a graphical representation  of what-eats-what in an ecological community. Like a food chain, it shows  the food relationship among organisms and how energy is transferred through them in the form of food. A food web shows a predator-prey relationship. A predator is an organism that eats another organism. The prey is the organism which the predator eats. Some examples of predator and prey are lion and zebra, bear and fish, and fox and rabbit.

Decomposers: Decomposers are organisms that break down substances into smaller and simpler substances such as mineral salts, carbon dioxide and water. This process is called decomposers. Bacteria and fungi are important decomposers . The decomposers only absorb a small amount of energy. The rest, such as nitrates and phosphorus are released in the environment. Some of them return to the soil and are absorbed by the plants. In this way, the substances are recycled. Decomposers carry out aerobic cellular respiration, taking in oxygen and giving out carbon dioxide. If there would be no decomposers, dead and waste matter would pile up and plants and animals would not be able to get their nutrients and would die.

Mushrooms are important decomposers

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